1. Technical Field
The present invention is related to a deicing composition and a method of using thereof, especially for aircraft runways and roads. In particular, the invention is related to a deicing composition comprising alkali metal salt of formic acid and an alkali metal silicate as the corrosion inhibitor.
2. Description of Related Art
In winter, snow and especially ice on the roads, highways, taxiways and runways make to lessen the traction and become the main source of danger and accidents thereof. The removal of snow or ice from such surfaces, is of great importance which will ensure safe traffic movements. The most efficient and known method of striving against the problem is to melt the ice by chemical salts which are currently applied to traffic areas in extensive amounts.
For deicing purposes, there have been conventionally described numerous alkali and alkaline earth metal salts of inorganic and organic acids and some organic compounds like urea as well, but in general, there are two essential drawbacks of deicer compounds to be forestalled, their corrosive action on metals especially on light metals such as aluminum or magnesium and their environmental impact. That is, together with the efficacy, deicers should also be unobjectionable in terms of corrosiveness and ecological and physiological effects. These can be significantly ruled out by combination of more environmentally benign chemical salts with suitable corrosion inhibitor(s).
In view of these requirements, the recent deicers revealed in the prior art as being advantageous are mainly alkali metal salts of organic acids as formates and acetates combined with specific corrosion inhibitors, comprising relatively complex mixtures, where these compositions should also exhibit low BOD and COD. Therefore, in the mitigation of above problems, the selection of the chemical salts and inhibitor(s) gains a greater importance.
It is, therefore, an object of the invention to obviate the disadvantages of the prior art.
Yet another object is, to provide a simpler, readily-prepared, and non corrosive deicer composition with very low environmental impact, for airport runways, highways and roads.
It has now been surprisingly found that a simplified composition, comprising at very specific combination of an alkali metal salt of formic acid as main ingredient and alkali metal silicate as the corrosion inhibitor in a very specific proportions, makes a novel and environmentally more preferred deicer (featuring a complete compliance with American Military Standards AMS 1431B).
The present innovation provides a novel and simpler deicing composition without requiring many additives or complex mixtures, which is a deicer for aircraft runways and roads. The said deicing composition comprises essentially
a) from 97.30 to 97.70% by weight of alkali metal salt of formic acid and
b) from 2.30 to 2.70% by weight of an alkali metal silicate as the corrosion inhibitor.
Component a) is an alkali metal formate. The alkali metal is preferably sodium. Accordingly, component a) is sodium formate (Industrial Grade: Assay min. 97%, the rest is pentaerythritols) which is much better than acetates in terms of BOD and COD.
Component b) is a water soluble alkali metal silicate, the alkali metal again being preferably sodium.
The novel and preferred deicing composition is prepared by mixing together the liquid or solid components. The deicing composition can be applied to the traffic areas in the customary manner, such as, spreading as solid powder or as granules of 2-4 mm in diameter or the like.